Zeeshan Ahmer

Abstract

An investigation on thermomechanical behaviour of a tool steel X38CrMoV5

Zeeshan Ahmer - 19 December 2011

Hot work tool steel X38CrMoV5-47HRC is mainly used in industrial manufacturing processes such as high pressure die casting, hot Forging, stamping and rolling etc. The tools should comprise high fatigue strength as well as high toughness to defy thermal and mechanical shocks. The tool's Surface is principally ruined by the cyclic and progressive process under ephemeral temperature i.e. the process of non-isothermal fatigue. The appropriate constitutive laws are therefore required to predict the behaviour of material under non-isothermal conditions.
This thesis depicts a contribution to predict the mechanical behaviour of X38CrMoV5-47HRC by numerical simulations using constitutive behaviour models. Assessment of the robustness and limitations of a Chaboche type thermoelastoviscoplastic model is carried out under several different test conditions starting from several uniaxial tests (LCF and TMF) to complex loading conditions with variable transient temperature range and variable amplitude of mechanical strain. After characterization of the model under the said conditions, its parameters have been re-identified in order to update the model to work under complex loading conditions. Keeping in view the model's limitations, further directions are also discussed in order to improve the model in terms of its application under severe loading conditions.

Keywords: Tool Steels, TMF, LCF, Constitutive Behaviour Model, Numerical Simulation

Last modified: 04/24/2012 05:58 PM